The present invention relates to an improved process for quenching coke in an installation utilizing a watertight one-spot quench car.
The recent introduction of a one-spot quench car has created some serious problems for the coke manufacturer in the quality of the coke produced. For example, hot coke which is deposited in a one-spot coke quench car from a six meter coke oven forms a high conical pile of hot coke, unlike a conventional car which has a flat profile, with the depth of bed of coke under the peak portion reaching as much as about twelve feet. Difficulty is experienced in getting sufficient quench liquid to all areas of the uneven bed of coke and hot spots in the coke are evident when the quenched coke is dumped on the wharf. The hot spots require additional manual quenching to avoid damage to conveyor equipment. Furthermore, a uniform moisture content throughout the bed of coke is desirable but practically impossible of attainment when conventional spray quenching is practiced.
It is the purpose of this quenching process to produce a quality coke having about 4% to about 10% by weight moisture content with a deviation of less than about .+-.4% from the average coke moisture of fifty pound samples taken from the car.
Many attempts have been made to apply quench liquid to a bed of hot coke in a manner that will "put out the fire" sufficiently to avoid hot spots while producing a quality coke having a relatively low and substantially uniform moisture content. For example, U.S. Pat. No. 3,806,425 to Eckholm et al discloses quenching coke with solid streams of quench liquid to drive the quench liquid to the bottom of the pile at spaced apart locations so that the quench liquid penetrates the depth of the bed prior to complete vaporization and percolates through the bed quenching coke as it goes. The quench liquid is continuously drained out of the bottom to prevent any accumulation thereof to avoid flooding.
U.S. Pat. No. 3,876,143 to Rossow et al describes a process for quenching coke by independent spray pipes arranged parallel to each other to extend along the length of the coke car. The coke car has an inclined support floor to provide a progressively decreasing depth of coke transverse to the car. The water discharged by each pipe is controlled to sprinkle the maximum depth of coke for an initial period followed by discharge from the other pipes onto successively decreasing depths of coke for progressively decreasing periods of time.
U.S. Pat. No. 1,677,973 to Marquard attempted to control the over and under-quenching of coke by applying a deluge of water through relatively wide angle sprays in five second periods at a rate of 150-200 gals. per second. The water was then allowed to drain and the step repeated for as many sequences as necessary to adequately quench the coke.
After considering these processes for controlling quenching of hot coke in which coke is pushed from a coke oven into a quench car to form peak portions, a process was discovered which applies the quench liquid in a manner and pattern that levels the hot coke and provides for a thorough and uniform quenching of the coke.